Abstract: A laser transmission system includes: a modulation module, a voltage-current conversion module, an electro-optic conversion module, an optic-electro conversion module, and a control module. The modulation module is configured to modulate an input voltage, and output a first voltage. An average value of the first voltage within a first duration is 0. The voltage-current conversion module is configured to output a first current based on the first voltage. The electro-optic conversion module is configured to output an optical signal corresponding to the first current. The optic-electro conversion module is configured to receive the optical signal from the analog optical fiber, and output a second voltage based on the optical signal. The control module is configured to determine an average value of the second voltage, and determine an electro-optic conversion coefficient of the electro-optic conversion module based on the average value of the second voltage.

Abstract: A signal transmission system includes a first laser signal transmission system, a second laser signal transmission system and a control module. The first laser signal transmission system includes an electric signal generation module, a first electro-optical conversion module and a first optical-electro conversion module. The electric signal generation module outputs a first current and a first voltage. The first electro-optical conversion module outputs a first optical signal. The first optical-electro conversion module outputs a second voltage. The second laser signal transmission system alternately inputs the first voltage and a calibration voltage and outputs a third voltage. The control module determines the first voltage based on the correspondence relationship between the calibration voltage and the third voltage and based on the third voltage, and determines a first electro-optical conversion coefficient based on a ratio of the first voltage to the second voltage.

Abstract: The application provides a closed loop current transformer, in which a hall element is positioned in a notch of a magnetic ring and is used for generating an induced voltage according to the magnetic field generated in the magnetic ring by current to be measured. A first compensating coil and a second compensating coil are wound on opposite sides of the magnetic ring in the same winding direction. An input end of the power amplifier circuit is connected with an output end of the hall element, and an output end is connected with the first compensating coil and the second compensating coil respectively. The other ends of the first compensating coil and the second compensating coil are respectively connected with a signal detection circuit, and an output end of the signal detection circuit is used as an output end of the closed loop current transform.

Abstract: The invention provides a signal isolation and transmission device, comprising a high-frequency amplitude modulation circuit, a signal demodulation circuit, a first H-field antenna and a second H-field antenna. The first H-field antenna and second H-field antenna are both loop antennas with an external conductive shielding layer, and an insulating layer is wrapped outside the conductive shielding layer. The annular parts of the first H-field antenna and second H-field antenna face and abut each other. The high-frequency amplitude modulation circuit is connected with a pin of the first H-field antenna, and a pin of the second H-field antenna is connected with the signal demodulation circuit. The signal to be tested is modulated onto a high-frequency carrier signal by the high-frequency amplitude modulation circuit, and then isolated and transmitted by the two H-field antennas, which greatly improves the anti-interference effect, reduces the attenuation degree and improves the coupling degree of the signals.

Abstract: The application provides an attenuator and a differential voltage probe, comprising a forward attenuation circuit and a reverse attenuation circuit which are symmetrical with each other, a first compensation unit and a third compensation unit which are symmetrical with each other, a second compensation unit and a fourth compensation unit which are symmetrical with each other, and a differential amplifier; the four compensation units are all adjustable capacitor units composed of constant capacitance; a positive-going signal to be tested is attenuated by the forward attenuation circuit, and frequency characteristics of a preset frequency point are adjusted by the first compensation unit and second compensation unit; a negative-going signal to be tested is attenuated by the reverse attenuation circuit, and frequency characteristics of a preset frequency point are adjusted by the third compensation unit and fourth compensation unit; finally, the difference value is calculated by the differential amplifier, ampli